Notes, summaries, assignments, exams, and problems for Geology

Magmatism and Volcanism

Magmatism and volcanism are fundamental geological processes related to the formation of magma and volcanoes.

Magmatism: Formation of Magma and Rocks

Magmatism is the process involving the formation of magma (a mixture of melted materials with minerals and gases) and magmatic rocks (formed from the consolidation of magma). Conditions conducive to rock fusion include:

• Temperature increase: Elevated temperatures cause rocks to melt.
• Pressure decrease: Reduced pressure allows rocks to expand and, consequently, melt.
• Presence of fluids: Water, in particular, significantly lowers the melting point of rocks.

Volcanism: Magma Reaching the Surface

Volcanism is the process by which magma reaches the Earth's surface, forming volcanoes... Continue reading "Earth's Dynamic Geology: Processes, Relief, and Risks" »

Earth Science Final Exam Review

April 14, 2025 – Lecture 18: Natural Resources – Energy and Mineral Resources

Natural Resources: An Introduction

Natural resources are materials or substances that occur in nature and can be used for economic gain. Humanity cannot create natural resources; they take millions, even billions, of years to form within Earth. Therefore, we are limited to what nature provides. Natural resources are broadly classified into eight groups: wildlife, air, wind, soil, water, fossil fuels, sunlight, and minerals (including precious metals like copper, gold, silver, nickel). Mineral resources, by definition, are inorganic, meaning they are not derived from living things (for example, coal is considered organic because it... Continue reading "Earth's Interconnected Systems: Resources, Climate, and Impact" »

Strike and Dip of Rock Beds

The strike and dip of a rock bed are key concepts in structural geology used to describe the orientation of a rock layer.

Strike

Strike is the direction of the line formed by the intersection of a rock surface with a horizontal plane. It is usually measured as an angle from north, with values ranging from 0° to 360°.

Essentially, strike indicates the compass direction of the rock layer as it extends across the landscape.

Dip

Dip is the angle at which the rock bed inclines from the horizontal plane. It is measured perpendicular to the strike direction and indicates the steepest angle of descent of the rock bed.

The dip has two components: the dip angle (measured in degrees from the horizontal) and the dip direction (the... Continue reading "Strike and Dip Measurement for Rock Bed Orientation" »

Energy resources: renewable and non-renewable

Energy resources are classified into renewable and non-renewable.

Renewable resources

Renewable resources include solar, wind, geothermal, hydropower, biomass, and wave and tidal energy. They regenerate naturally and have a reduced environmental impact.

Non-renewable resources

Non-renewable resources include fossil fuels (hard coal, lignite, peat, petroleum, natural gas and oil shales) and nuclear fuels (uranium, thorium and plutonium), as well as fusion fuels (deuterium, tritium and lithium), whose resources are much larger than those of fossil fuels.

Forms of energy and conversion

Energy can appear in mechanical, electrical, thermal, chemical, solar or nuclear form, and it can be converted from one form... Continue reading "Global Energy Resources, Conversion, and Reserves" »

Soybean

Requires warm areas and medium-textured soils.

Neutral pH preferred; drought-tolerant.

Sowing from August 20th to August 30th.

Seeding rate: 2.5–4 kg/ha, spacing: 12.5 cm.

Nutrition and Fertilization

Nitrogen (N) requirements vary, with 0–30 kg N/ha. 9 Phosphorus (P), 30 Potassium (K).

Herbicides applied pre-emergence; insecticides for pest thresholds.

Harvest

Chemical desiccation harvest, 10 days after, at 12-16% moisture.

Dry seeds to 8% for storage.

Oilseed Rape

Typical rotation: Winter wheat, oilseed rape, spring barley.

Avoid planting oilseed rape within 4 years on the same field.

Medium-textured soils with good aeration.

Frost-resistant; requires adequate nutrient supply. Needs vernalization.

Early sowing by late August.

Plant density: 30-... Continue reading "Cultivation Practices for Key Crops: From Sowing to Harvest" »

117 Ways to Pass the Earth Science Regents

1. The same substance always has the same density.

2. As pressure increases, density increases.

3. As temperature increases, density decreases.

4. Water expands when it freezes.

5. Most changes are cyclic.

6. Water is most dense at 4^oC, when it is a liquid.

7. The true shape of the Earth is an oblate spheroid, but from space it looks like a sphere.

44. As temperature increases, air pressure decreases.

45. As moisture increases, pressure decreases.

46. Air pressure decreases with altitude.

47. Highs are cool and dry; lows are warm and wet.

48. Wind is due to air pressure differences.

49. Wind blows from high to low pressure.

50. Wind is named from the direction that it is coming from.

51. The accepted value is the... Continue reading "Earth Science Regents: 117 Key Concepts" »

Environmental Laws

Republic Act No. 6969 — Toxic Substances Act

Republic Act No. 6969 (Toxic Substances and Hazardous and Nuclear Wastes Control Act of 1990)

Regulates toxic substances and hazardous waste.

Penalties: Fines up to ₱500,000 or imprisonment (6–12 years).

Republic Act No. 8749 — Philippine Clean Air Act

Republic Act No. 8749 (Philippine Clean Air Act of 1999)

Establishes air pollution control policies.

Penalties: Fines of ₱10,000–₱100,000 per day; suspension of permits.

Republic Act No. 9003 — Ecological Solid Waste Management

Republic Act No. 9003 (Ecological Solid Waste Management Act of 2000)

Implements solid waste management programs.

Penalties: Fines of ₱1,000–₱1,000,000; suspension of permits.

Republic Act No. 9275

Harnessing Solar Power: Technologies and Potential

Solar power plants are facilities that harness the energy that reaches the Earth from the Sun in the form of electromagnetic radiation. This source is practically inexhaustible and has enormous potential, as the solar energy that reaches the Earth in one hour exceeds the global annual energy consumption.

Key Solar Energy Conversion Technologies

Solar radiation can be converted into electrical or thermal energy through different technologies, each with its own specific characteristics:

1. Photovoltaic (PV) Solar Energy

Photovoltaic solar energy is based on the use of panels made of semiconductor cells capable of transforming light into electricity through the photoelectric effect. Key operational... Continue reading "Solar Energy Technologies: PV, Thermal, and CSP Explained" »

Sources of Earth's Internal Heat

The Earth's internal heat, the engine driving many geological processes, originates from several key sources:

• Primordial Heat: This is the leftover heat from the planet's initial formation and accretion.
• Core Formation: Significant heat was released as heavy elements, primarily iron and nickel, sank to form the Earth's core.
• Radioactive Decay: The continuous decay of radioactive isotopes within the crust and mantle, such as uranium-238, thorium-232, and potassium-40, is a major source of heat.
• Latent Heat: Heat is released from the crystallization and solidification of the liquid outer core to form the solid inner core.
• Tidal Heating: Frictional heat is generated by the gravitational forces exerted by the Moon and